Injury can result from a wide range of sources, both from accidents at home or as the result of medical treatment. Potential pathogens can use injury as an entry site and cause infections. The balance of activating wound repair and inhibiting infection challenges an organism to regulate these distinct processes with precise control. Failure to control wound repair can lead to cell proliferation and scarring. Lack of efficient immune response can cause increased tissue damage. Drosophila provides a powerful genetic system to navigate the genes that regulate wound repair. Current reports of patients suffering from chronic wound conditions have surpassed 6 million cases and this does not include the millions more recovering from surgical or traumatic wounds. Discovery of conserved genetic paradigms for response to cellular damage and infection in the model organism Drosophila will directly impact the development of improved strategies for tissue repair. The embryonic epidermis of very late stage Drosophila embryos provides an in vivo system for wound response analysis. The objective of this particular application is to gain new insight into mechanisms that restrict the spread of damaged cells and infection. The central hypothesis of this proposal is that restricting the localization of damage signals only to effected regions will improve repair and increase survival after infection. Guided by strong preliminary data, this hypothesis will be teste by pursuing two specific aims: 1) determine the cellular mechanism for restricting DNA damage to the site of injury; 2) analyze the role of wound response activators and inhibitors during wound repair. The applicant has a strong background in Drosophila genetics and has characterized a set of evolutionarily conserved genes that regulate the localization of a transcriptional response to epidermal injury. Under the first aim, the investigation of the how DNase II genes are transcriptionally regulated at the site of injury will provide context for molecular mechanisms that promote wound localization. Under the second aim, new transgenes will be developed to test the function of wound activator and wound inhibitor genes following injury and microinjection. Molecular cloning techniques and fluorescence microscopy will be used to accomplish the two specific aims. The use of a transcriptional activation reporter provides an innovative approach to uncover well-conserved components that promote the localization of a response during epidermal injury and may influence other pathological conditions of tissue damage. The proposed research is significant because the outcomes should be easily translatable to mammalian systems.